In general, the switching of the main switch of a converter is hard-switching, which will cause serious loss. For the purpose of solving the above problem, soft-switching technology is developed. Generally speaking, the way to implement soft-switching technology is to integrate an auxiliary circuit with the circuit of a converter for the converter to achieve soft-switching (i.e. zero-current switching and zero-voltage switching).
There are many currently available soft-switching circuits are developed; for example, Taiwan Patent Publication No. 201436437 discloses a high-efficiency bidirectional single-input and multi-outputs DC/DC converter; Taiwan Patent Publication No. 200703857 discloses as high-efficiency bidirectional converter for power sources with great voltage diversity; China Patent Publication No. 104143919 discloses a bidirectional DC converter; however, the above currently available soft-switching circuits still have a lot of shortcomings to be overcome.